scripts: make python shebangs specific about desired version

The RPM packaging tools like to make sure that all packaged python
scripts have version-unambiguous shebangs. Be more specific about the
desired python version in a couple of places to avoid having to disable
these checks in make rpm-pkg.

Signed-off-by: Uday Shankar <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>

scripts/show_delta

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # SPDX-License-Identifier: GPL-2.0-only
 #
 # show_deltas: Read list of printk messages instrumented with

scripts/tracing/draw_functrace.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # SPDX-License-Identifier: GPL-2.0-only
 
 """